Wireless-telephone transmitter.



A. A. JAHNKE. WIRELESS TELEPHONE TRANSMITTER APPLICATION FILED SEPT. 21, 1903.

948,609. I Patented Feb. 8, 1910,

a i i r 1 5; 14 73/ 4 2i 26 wrmassss fi INVENTQR ATTORN EV m 1:1 Mwrn To all it may concern:

ALBERT JAHNKE, OF SAN FRANCISCO, CALIFORNIA; ASSIGNOR F ONE-HALF T0 SUSAN C. TATE, OF SAN FRANCISCO, CALIFORNIA.

WIRELESSTELEPHONE TRANSMITTER.

Specification of Letters Patent.

Patented Feb. 8, 1910.

Application filed September 21, 1908 Serial No. 454,095.

Be it known that I, ALBE RT A. J AHNKE, a citizen of theUnited States, residing at San Francisco, in the county of San Francisco and State of Cal fornia, have invented new and useful Improvements in VVireless-Telephone Transmitters, of which the following is a specification.

\ The object of the present invention is to provide an improved telephone transmitter, especially adapted for wireless telephones,

' which will be more eflective and powerful in 1 its action'tha'n' those heretofore employed.

' male.

In the accompanyingdrawing, the figure is a vertical section of the apparatus.

Referring to the drawing, 1 indicates 'a casing of a telephone transmitter, .and 2 the mouth piece thereof, screwed to the casing, and between which and the casing is clamped the main diaphragm 3, whichls of metal, and of the usual construction.

4, 5, indicate metal tubes, which at their inner ends are secured to thin, arranged, radio-platinum disks or electrodes 6, 7. Uponor around said tubes, and behind said platinum disks, are metallic cup-shaped terminals 8, 9, andupon said tubes; behind said terminals, are circular sheets 10, 11, of mica. Nuts 12, 13 are then screwed upon said tubes behind said mica sheets .to hold them in place against the cup shaped termi- The outer ends of the tubes are now" centrally screwed, one through the diaphragm and the other through the back'of the casing, nuts 14, 15, 16, 17, being provided to secure them in place. Into said tubes are inserted tubes 18, 'of glass or other suitable material, the tubes 4, 5, being formed with or other volatile hydrocarbon fluid is suppliedthrough said glass tubes and runs out through said apertures 19 into the cupshaped terminals. The function of the al-- cohol 'in these terminals is to maintain the electr des at a uniform temperature and'prevent --o erheating of the same, by the cooling effect of the eva orationwhich takes place when the electro es become heated owing to the passage-of the current.

20 indicates a cylindrical wall formed of lava or mineral talc, which, with the two sheets of mica, forms a box. The edges of the mica sheets are clamped upon the cylindrical wall 20 bymeans of a hollow annular clamp 21, the inner side of which is open and receives the edges of the mica sheets and the oppositely lava wall, and is clamped thereon by means of screws22. Said clamp thus forms a reservoir, into which alcohol can be supplied by means of a supply tube 24'. The box is filled with granules which may be, as usual, of carbon. But I prefer to use carborundum since it withstands heating effect of a large current. The current supply wires 25, 26 are connected as shown to the respective electrodes. V

The following is the operation of the transmitter: The annular reservoir and the hollow electrode terminals having been filled with alcohol, the alcohol permeates through the lava and passes into the box containing the carbon or carborundum granules. \Vhen sound waves impinge. upon the main diaphragm and on that account the two electrodes approach each other, and consequently the resistance of the carbon is diminished, the efiect is to heat the electrodes" This results in an increased vaporization of the alcohol, which increases the conductivity of the carbon or carborundum granules, so that 'thecurrent in the transmitter circuit is. correspondingly increased. Obviously the reverse takes placewhen the electrodes recede.

from each other. I I claim ber containing granularmaterial, and having a porous wall, and means for supplying a volatile liquid through said wall to said chamber, substantially as described.

'2. A telephone transmitter having a cham-' ber, end walls of which areformed by vibrating diaphragms, and having an annular porous wall, granular material in said chamher, and a chamber surrounding said porous wall and adapted to contain a volatile liquid, substantially as described.

' 3. A telephone transmitter comprising oppositely disposed mica sheets, cup-shaped terminals carried by said sheets,means for supplying said terminals with a volatile'licp uid, gra-nulanmaterial between said sheets, electrodescarriedby said sheets, and means for moistening the granular material with the volatileliquid, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

' ALBERT A. JAHNKE. Witnesses:

F. M. WRIGHT,

vD. B. Rronanne.

I '1; A telephone transmitter having a chem-- 

